Process of dyeing raw silk



lPntented tiller. ill,

EUGENE l3. LLUZIFAI, GE NEW YORK, it". Y.

Ho Drawing.

To a?! whom it may concern:

Be it known that I, EUGENE L. Maori-.1, a

citizen of the l nited States America, re-

siding at New York city, New York County, a State of New York, have invented certain new and useful Improvements in Processes of Dyeing Raw Silk, of which the following is a specification. v

My invention relates to a process of dye ing grege or raw silk (single end, not thrown) with developed or diazo colors, or any colors that can be developed with an alkali, or such developers as are used in conjunction with these dyes, and the invention is has for its object to provide an inexpensive and eilicient dyeing process whereby to eliminate throwing" of the untvtisted silk and effect dyeing of the same .with diazo or snnilar developed colors, the invention consistin generally in first dyeing the untwisted sil r, then diazotizing it to harden the gum and fixing the color, and then developing it, all as hereinafter more fully described and claimed.

In carrying out my improved process, I first impregnate the silk in a bath containing the desired diazo dye, or any developed color, with the addition of approximately 5% to 10% acetic acid, or any acid comgo monly used in dyeing. Thereafter the silk is Washed-in a bath of cold water. i then subject the silk to a diazotizing bath, consisting of a solution of cold Water and approximately 3% to 5% of sodium nitrite and 85 about 5% of sulphuric or similar acting acid per weight of material used; for certain colors the percentage is decreased or increased. This latter step produces a hardening of the cereceous or gummy substances as and fixes the colors.

Thereafter the silk is thoroughly washed in cold water, and it is then subjected to an alkali developing bath consisting of approximately 5%t0 10% of sal soda or any other as developer commonly used with developed colors, such as beta naphtol.

' I then again wash the silk in either cold application filed April 223, i923.

ficrial Etc. 634,1?"3.

or warm water. It is then dried and Woven and may be deguinmed while in the piece.

By my improved process I am able to eliminate throwing and thereby dye colors fast to boiling oil and bleaching on single end grege, which so far as I am aware has heretofore never been accomplished.

What I claim and desire to secure by Letters Patent is 1. The process of treating raw untwisted silk, which consists in first dyeing it, then diazotizing it to harden the gum in the silk and fix the color, and then subjecting it to a developing solution,

The process of treating untwisted or grege silk, which consists in first impregnating the silk in a diazo dye, then Washing the silk. then impregnating the silk in a diazotizing bath, then again Washing the silk, and then subjecting it to an alkali developingbath.

3. A step in the process of dyeing grege or untwisted silk, which consists in initially dyeing it with diazo colors, and then in a single operation hardening the gummy substances in the silk and fixing the colors.

l. The process of dyeing untwisted rawsilk, which consists in first dyeing the silk with diazo or similar dyes, then washing the silk, then impregnating the silk in a diazotizing bath comprising Water andsulphuric acid and sodium nitrite, then again washing the silk, and finally subjecting the silk to a developing bath,

5. The process of dyeing untwisted raw silk, which consists in first impregnating the silk in a bath containing asuitable dia'zo dye with the addition-of acetic acid, then washing the silk, then subjecting it to a diazotizin solution of sodium nitrite and sulphuric acid to harden the gummy substances in the silk, then washing the silk, then immersing it in an alkali developing 90 bath, then again washing the silk and then drying weaving and degumm ing tliih silk.

EUGENE L. MAUPAI. 

